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Abstract:

The present invention relates to an insulating and draining board with
two opposing main side surfaces and a top side portion and a bottom side
portion, said board being formed by bonded beads of foamed plastic,
wherein pores are present between the beads forming a network for
drainage of water, which bottom side portion of the board being tapered
towards a first free end extending in the longitudinal direction of the
board, the first free end being located between planes coinciding with
the main side surfaces.

Claims:

1. An insulating and draining board with two opposing main side surfaces
and a top side portion and a bottom side portion-, said board being
formed by bonded beads of foamed plastic, wherein pores are present
between the beads forming a network for drainage of water, which bottom
side portion of the board being tapered towards a first free end
extending in the longitudinal direction of the board, the first free end
being located between planes coinciding with the main side surfaces.

2. The insulating and draining board according to claim 1, wherein said
bottom side portion being tapered towards one or more additional free
ends.

3. The insulating and draining board according to claim 2, wherein each
additional free end being located between the planes coinciding with the
main side surfaces.

4. The insulating and draining board according to claim 1, wherein a
groove is provided in the top side portion with a shape complementary to
the shape of the tapering bottom side portion.

5. The insulating and draining board according to claim 1 wherein the
bottom side portion has a cross-section comprising at least one V-shaped
or U-shaped portion.

6. The insulating and draining board according to claim 1 wherein the
bottom side portion has a V-shaped, U-shaped, or W-shaped cross-section.

7. The insulating and draining board according to claim 1, wherein the
beads of foamed plastic have an average diameter below 7 mm.

8. The insulating and draining board according to claim 1, wherein the
beads of foamed plastic are bonded by means of a binding agent.

9. The insulating and draining board according to claim 1, wherein the
draining board comprises at least one impregnating agent.

10. The insulating and draining board according to claim 9, wherein the
impregnating agent is selected from the group consisting of flame
retardant, sodium silicate, and potassium silicate, or combinations
thereof.

11. The insulating and draining board according to claim 9, wherein at
least some of the bonded beads are surface coated with the impregnating
agent.

12. The insulating and draining board according to claim 1, wherein the
board has a length between 500 and 2000 mm, a thickness between 30 and
500 mm, and a height between 250 and 4000 mm.

13. The insulating board according to claim 1, wherein the foamed plastic
is selected from the group consisting of polystyrene and expanding
polystyrene.

14. A method for production of an insulating and draining board,
comprising: providing a mixture of beads of foamed plastic and binding
agent shaping said mixture into a board structure with two opposing main
side surfaces, drying and/or hardening the board structure such that the
beads of said mixture are bonded by means of said binding agent,
providing the board structure with a bottom side portion being tapered
towards a first free end extending in the longitudinal direction of the
board, the first free end being located between planes coinciding with
the main side surfaces.

15. The method according to claim 14, wherein the step of providing the
board structure with a bottom side portion occurs in a casting or
moulding operation integrated with the step of shaping.

16. The method according to claim 14, wherein the step of providing the
board structure with a bottom side portion occurs in a cutting operation.

17. An insulating and draining board with two opposing main side surfaces
and a top side portion and a bottom side portion, said board being formed
by bonded foamed beads, wherein pores are present between the beads
forming a network for drainage of water, wherein the pores exhibit a pore
size varying in a thickness direction of the board, such that the
draining efficiency varies in said thickness direction.

18. An insulating and draining board with two opposing main side surfaces
and a top side portion and a bottom side portion, said board being formed
by bonded beads arranged in at least two layers being parallel to said
main surfaces, wherein pores are present between the beads forming a
network for drainage of water, wherein a property of one of said at least
two layers is different from the corresponding property of another of
said at least two layers, the property being selected from the group
consisting of bead material, binding agent, average diameter of beads,
pore size, and degree of close packing of the beads, or combinations
thereof.

Description:

TECHNICAL FIELD

[0001] The present invention relates to an insulating and draining board
and specifically such boards made of foamed plastics.

BACKGROUND

[0002] Buildings, such as houses, or other constructions, may be partly
made from boards of foamed plastic having insulating properties. Such
boards may be exposed to water originating from rain or humid air
contacted with the building, which water may cause damages to the boards
and the building.

[0003] The US patent with U.S. Pat. No. 4,586,304 discloses insulated
siding panels containing a panel of hardboard and a polystyrene foam
layer with upper and lower faces having V-shape. The polystyrene foam is
a non-draining moisture vapour barrier and a network of channels is
provided between the hardboard and the foam layer to transmit moisture
vapour.

[0004] Thus, there is a need for boards made from foamed plastic with
efficient draining properties.

SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to make available an
efficient insulating and draining board, as well as a method for
production of an efficient insulating and draining board.

[0006] According to a first aspect of the invention, the object is
achieved by means of an insulating and draining board with two opposing
main side surfaces and a top side portion and a bottom side portion, said
board being formed by bonded beads of foamed plastic, wherein pores are
present between the beads forming a network for drainage of water, which
bottom side portion of the board being tapered towards a first free end
extending in the longitudinal direction of the board, the first free end
being located between planes coinciding with the main side surfaces.

[0007] An insulating board may be suitable material for building of for
example houses, as such a board may lend the house energy saving
properties.

[0008] A draining board may be suitable material for building for example
houses, as such a board may remove water from the house, thus minimising
risk of damage to the house as a result of the water.

[0009] The term water may refer to water in liquid, gaseous, or vapour
phase, or combinations thereof; water in any of these phases may have
been converted from another one of these phases, or water being in
equilibrium between two or more of these phases; and mixes thereof.

[0010] Beads of foamed plastic are suitable material for the boards
according to the invention, as such beads are easy to handle prior to
producing the boards, as such beads results in low weight of the boards,
and as such beads results in good insulating properties of the board.
Further, such material may efficiently be bonded according to the
invention to form boards. Yet further, such material of foamed plastic
results in a low consumption of plastic material even for producing large
volumes of board. Foamed plastic results in boards with low density and
thus, for example, easy handling of the boards.

[0011] The board being formed by bonded beads may result in boards
suitable for use as building material, with suitable properties with
regards to, for example, resistance towards breakage, bending and
compression; and load bearing capacity, or other suitable properties.

[0012] The term foamed plastic may also be referred to as cellular plastic
or expanded plastic.

[0013] The use of beads, according to the invention, efficiently creates
pores between the beads, which pores are present between the beads
forming a network for drainage of water. Thus, water present in the
boards may be drained from the boards by, for example, gravity and/or
movements of air. The pores forming a network may allow water to be
ventilated through the board. Thus, water present in the board may be
removed by air. Furthermore, small droplets of water, vapour of water,
and/or water in gas phase, present in the ambience of the board may be
ventilated through the boards. Further, vapour being condensed inside the
board, for example as a result of movement of air through the board and a
temperature gradient across the board acting such that the temperature of
the air is reduced, or water entering the board as liquid, may be
ventilated out of the board by air, or be drained from the board by
trickling downwards by gravity, or a combination thereof. The draining of
water from the board may be through flowing, running, trickling or
dripping, or combinations thereof, depending on, for example, the amount
of water being drained from the board.

[0014] Thus, the board according to the invention may prevent water from
being present in the board or minimise or reduce the amount of water
being present in the board, or any construction comprising the board.

[0015] It is a further benefit with the board according to the invention,
that the use of the board may omit the need for ventilation channels, for
example channels between the board and any material in contact with the
main side surfaces of the board, such as a wall siding, to remove water.

[0016] The board according to the invention being tapered towards a first
free end extending in the longitudinal direction of the board, the first
free end being located between planes coinciding with the main side
surfaces, may result in that water being drained downwards through the
board is drained from the board at a distance from the main side surfaces
and between planes coinciding with the main side surfaces. Thus, water
may kept away and drained away from the main side surfaces. Thus, water
may kept away and drained away from any material in contact with the main
side surfaces. The tapering may results in a concentration or focusing of
the water being drained from the board towards the first free end
extending in the longitudinal direction of the board, thus in the case of
another board being positioned below the board, the water may
advantageously be entering said another board at a distance from the main
sides of said another board and be drained downwards through said another
board between the main side surfaces of said another board.

[0017] Furthermore, the tapering may result in less water being retained
in the board after water has been drained through the board.

[0018] The bonded beads may lend the board a coarse or rough surface
suitable for holding materials such as plaster, stucco, paint, or putty.

[0019] The bottom side portion may be tapered towards one or more
additional free ends, according to one embodiment of the invention.

[0020] Said each additional free end may be located between the planes
coinciding with the main side surfaces. Thus water may kept away and
drained away at a distance from the main side surfaces. Thus, water may
kept away from and drained away from any material in contact with the
main side surfaces. As one result, any material being in contact with the
main side surfaces, such as plaster, stucco, paint, sidings, insulation,
or wooden building material, may be prevented from being damaged or in
other ways affected by the water.

[0021] A groove may be provided in the top side portion with a shape
complementary to the shape of the tapering bottom side portion. Thus,
efficient and close positioning of one board on top of another may be
realised. Thus, efficient isolation may be obtained and efficient
mounting of boards during, for example, building of, for example, houses.
Furthermore, water being drained from one board at distance from the main
side surfaces positioned on top of another board, may enter said another
board at a distance from the main side surfaces of said another board.

[0022] The bottom side portion may have a cross-section comprising at
least one V-shaped or U-shaped portion. Such cross-sections may be
suitable for providing the board with good draining properties, and water
drained from the board may efficiently be kept away from the main side
surfaces.

[0023] The bottom side portion may have a V-shaped, U-shaped, or W-shaped
cross-section. Such a shaped bottom side portion, may be suitable for
providing the board with good draining properties and water drained from
the board may efficiently be kept away from the main side surfaces.

[0024] The bottom side portion may have an unsymmetrical V-shape, with the
apex of the V being closer to one of the planes coinciding with the main
side surfaces than the other. It may be preferred that the point of the V
being positioned at a distance, as seen in the transverse or thickness
direction of the board, from one of the planes coinciding with the main
side surfaces of less than 50% of the thickness of the board, it may be
more preferred that said distance from one of the planes coinciding with
the main side surfaces is less than 40%, and it may be most preferred
that said distance from one of the planes coinciding with the main side
surfaces is less than 25%. With such a shaped bottom side portion, water
drained from the board may efficiently be kept away from both main side
surfaces, and it may be particularly kept away from one of the sides,
i.e. the side coinciding with the plane furthest away from the first free
end, as compared to the plane coinciding with the other side as compared
to the other side.

[0025] The first free end extending in the longitudinal direction of the
board may be closer to one of the planes coinciding with the main side
surfaces. It may be preferred that the first free end being positioned at
a distance from one of the planes coinciding with the main side surfaces
of less than 50% of the thickness of the board, it may be more preferred
that said distance from one of the planes coinciding with the main side
surfaces is less than 40%, and it may be most preferred that said
distance from one of the planes coinciding with the main side surfaces is
less than 25%. With such a shaped bottom side portion, water drained from
the board may efficiently be kept away from both main side surfaces, and
it may be particularly kept away from one of the sides, i.e. the side
coinciding with the plane furthest away from the first free end, as
compared to the plane coinciding with the other side.

[0026] The main side coinciding with the plane at the closest distance to
the first free end may be selected as the utmost side of the board when
mounted or build into, for example, a building, i.e., for example, the
side closest to the exterior of a house. Thus, water drained by the board
may be kept far away from any interior constructions or materials such as
inner insulation, board materials or panels, and still be kept away from
any material in contact with the board on the outside of the house, such
as sidings, stucco, paint, or plaster.

[0027] The term beads refers to particles having irregular or regular
shapes and the use of the term diameter for defining the dimension of
such particles relates to a largest dimension of the particle.

[0028] The beads of foamed plastic may have an average diameter below 7
mm, for example, the beads of foamed plastic may have an average diameter
below 4 mm. All beads may be below 7 mm. Beads with such sizes may
provide efficient insulation properties. Further, beads with such average
diameters may provide efficient draining of water. Yet further, beads
with such average diameters may provide boards with high strength.

[0029] The beads of foamed plastic may be bonded by means of a binding
agent. Thus efficient bonding may be achieved. Such a bonding may be
strong and a board produced by such a bonding may be easily produced.

[0030] The binding agent may comprise compounds selected from the group
consisting of PVA and acrylate, or combinations thereof.

[0031] The draining board may comprises at least one impregnating agent.

[0032] The impregnating agent may comprise a flame retardant. The
impregnating agent may be selected from the group consisting of flame
retardant, sodium silicate, and potassium silicate, or combinations
thereof. Such impregnating agents may reduce the risk of the board
catching fire.

[0033] At least one impregnating agent may provide desired properties to
the board. For example, the hydrophilicity of the board may be decreased.
Thus, for example, water draining properties of the board may be
improved. Sodium silicate, and potassium silicate, or combinations
thereof, may improve the water draining properties of the board.

[0034] At least the portion of the bonded beads facing the surroundings,
i.e. the surface of the board, may be surface coated with the
impregnating agent. Surface coating is efficient as the required amount
of impregnating agent may be kept low. Further, the surface of the beads
may be the most efficient positioning of impregnating agents.

[0035] Essentially all beads may be surface coated with the impregnating
agent. Thus, the effect of the impregnating agent may be improved.

[0036] The impregnating agent may be mixed with the binding agent and thus
the impregnating agent may be applied to the beads simultaneously with
the binding agent and in one step.

[0037] The board may have any suitable dimension. For example, the board
may have a length between 500 and 2000 mm, for example 600-1800 mm such
as 1200 mm, a thickness between 30 and 500 mm, for example 50-300 mm, and
a height between 250 and 4000 mm, for example 300-3000 mm. Such
dimensions of boards may be suitable for building of for example houses.

[0038] Boards according to the invention may be suitable for use as wall
materials. Further, the boards may be suitable for use underground and/or
above ground, for efficient draining of, for example basements, or walls
in buildings. Yet further, the board may be used in combination with
other wall materials. The board may be used combined with other wall
materials, wherein the board is positioned on the side of the other wall
material exposed to the in average highest humidity. For example, a board
according to the invention may be positioned on the outside of a wall of
a house, i.e. on the side of the wall of the house exposed to rain or
water from the ground.

[0039] The foamed plastic may be selected from the group consisting of
polystyrene and polystyrene. Such foamed plastics may be suitable for
producing boards according to the invention and such foamed plastics may
lend boards according to the invention desired properties.

[0040] According to another aspect of the invention, the object is
achieved by a method for production of an insulating and draining board,
comprising: providing a mixture of beads of foamed plastic and binding
agent; shaping said mixture into a board structure with two opposing main
side surfaces; drying and/or hardening the board structure such that the
beads of said mixture are bonded by means of said binding agent;
providing the board structure with a bottom side portion being tapered
towards a first free end extending in the longitudinal direction of the
board, the first free end being located between planes coinciding with
the main side surfaces.

[0041] Providing a mixture of beads of foamed plastic and binding agent
may result in most or all of the beads being in contact with the binding
agent.

[0042] Shaping said mixture into a board structure with two opposing main
side surfaces is an efficient way of achieving a board structure.

[0043] Drying and/or hardening the board structure such that the beads of
said mixture are bonded by means of said binding agent may be an
efficient way of obtaining a board structure suitable for use as building
material, with suitable properties with regards to, for example,
resistance towards breakage, bending and compression; and load bearing
capacity or any other desired properties.

[0044] Providing the board structure with a bottom side portion being
tapered towards a first free end extending in the longitudinal direction
of the board, the first free end being located between planes coinciding
with the main side surfaces, may be an efficient way of obtaining a board
with desired draining properties according to the discussions above
concerning the board.

[0045] The step of providing the board structure with a bottom side
portion may occur in a casting or moulding operation integrated with the
step of shaping. Thus, efficient production of the board may be achieved.

[0046] The step of providing the board structure with a bottom side
portion may occur in a cutting operation. The cutting operation may be
for example any for the purpose suitable type of cutting the board, for
example, cutting or sawing, wherein the cutting may be realised by means
of, for example, a heated wire or heated knife.

[0047] The method according to the invention may further comprise a step
of providing an impregnating agent to the surface of the bonded beads.
Thus, properties of the board may be improved by means of impregnating
agent.

[0048] The impregnating agent may be agent for reducing the surface
tension of the board. Further, the hydrophilic character of the board may
be altered by the impregnating agent. For example, the hydrophilic
character of the board may be reduced, which may result in improved
draining properties of the board.

[0049] The impregnating agent may be applied to the board by soaking or
submerging the board in impregnating agent or by spraying the board with
impregnating agent, or in any other suitable way of depositing the
impregnating agent to the board. Such application of the impregnating
agent may be efficient for coating a large part of the surfaces of the
bonded beads with impregnating agent.

[0050] Relevant parts of the explanations given above with regard to the
device are also applicable to the method. Reference is hereby made to
these explanations.

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG. 1 illustrates a perspective view of a board according to the
invention.

[0052]FIG. 2a illustrates a perspective view of two boards having bottom
side portions having V-shaped cross-sections and grooves provided in the
top side portions with a shape complimentary to the shape of the bottom
side portion, one board being positioned on top of another.

[0053] FIG. 2b illustrates the short sides of two boards draining water as
viewed in the longitudinal direction of the boards, one board being
positioned on top of another.

[0054] FIG. 3a illustrates a short side of a board having a bottom side
portion having a V-shaped cross-section, as viewed in the longitudinal
direction of the board.

[0055] FIG. 3b illustrates a short side of a board having a bottom side
portion having a W-shaped cross-section, as viewed in the longitudinal
direction of the board.

[0056] FIG. 3c illustrates a short side of a board having a bottom side
portion having a U-shaped cross-section, as viewed in the longitudinal
direction of the board.

[0057] FIG. 3d illustrates a short side of a board having a bottom side
portion having a V-shaped cross-section, as viewed in the longitudinal
direction of the board.

[0058] FIG. 4a illustrates a short side of a board having a bottom side
portion having a V-shaped cross-section, and a groove provided in the top
side portion with a shape complementary to the shape of the bottom side
portion, as viewed in the longitudinal direction of the board.

[0059] FIG. 4b illustrates a short side of a board having a bottom side
portion having a W-shaped cross-section, and a groove provided in the top
side portion with a shape complementary to the shape of the bottom side
portion, as viewed in the longitudinal direction of the board.

[0060] FIG. 4c illustrates a short side of a board having a bottom side
portion having a U-shaped cross-section, and a groove provided in the top
side portion with a shape complementary to the shape of the bottom side
portion, as viewed in the longitudinal direction of the board.

[0061] FIG. 4d illustrates a short side of a board having a bottom side
portion having a V-shaped cross-section, and a groove provided in the top
side portion with a shape complementary to the shape of the bottom side
portion, as viewed in the longitudinal direction of the board.

[0062] FIG. 5 illustrates two boards of which the left board is a board
according to the invention and the right board is not a board according
to the invention.

DETAILED DESCRIPTION

[0063] The invention will now be explained in more detail, and specific
preferred embodiments, and variations of these, will be shown. The
explanations are intended for illustrative and explanatory purposes and
are not to be seen in any way as limiting the scope of the invention. The
illustrations are schematic and all details are not illustrated, and all
illustrated details may not be necessary for the invention.

[0064] A specific embodiment of the invention will now be discussed with
reference to FIG. 1.

[0065] An insulating and draining board 1 according to one embodiment of
the invention is illustrated in FIG. 1. The board 1 has two opposing main
side surfaces 3 and 3', of which only one side surface 3 is visible in
FIG. 1. When used as building materials, for example as part of a wall of
a house, the side surfaces 3 and 3' may be positioned such that they are
parallel to the surface of the wall such that the longitudinal direction
of the board is parallel to the horizontal direction of the wall.

[0066] The board 1 is formed by bonded beads of foamed plastic, wherein
pores are present between the beads forming a network for drainage of
water. Thus, water present in the board 1, may be drained from the board
1. Water may enter the board for example from any of the main side
surfaces 3 and 3', for example as the result of rain hitting the side
surface or rain hitting any material in contact with the side surface and
reaching the side surface through for example cracks or holes in the
material being in contact with the surface. Additionally or alternatively
water may enter the board for example as the result of air containing
water entering the board, the water being for example in gas phase or
vapour, for example, as the result of wind or draught, or other type of
transfer. Water present in the air as gas or vapour may condense in the
board, for example as the result of the temperature of the air being
decreased inside the board. Water may be drained from the board as a
result of water drops or small streams of water trickling or running
downwards through the pores present between the beads forming a network,
as the result of for example gravity. Draining water will reach the
bottom side portion 4, and leave the board through the bottom side
portion 4, wherein a major part of the water will leave the board at or
in the proximity of the free end 6 extending in the longitudinal
direction of the board at a distance from the main side surfaces 3 and 3'
and between planes coinciding with the main side surfaces. One result of
this is that wetting of the main side surfaces 3 or 3' and/or any
material in contact with the main side surfaces 3 or 3' is reduced,
minimised or avoided. Thus damages or undesired effects resulting from
such wetting is reduced, minimised or avoided. Such damages may be for
example, frost erosion or frost shattering, dissolving of the material,
fungi growth, or mould growth. In this example the bottom side portion 4
has a V-shaped cross-section 5. A groove 2 is provided in the top side
portion 7 with a shape complementary to the shape of the tapering bottom
side portion, thus allowing positioning of a similar or identical second
board on top of or below the illustrated board 3.

[0067] The bonded beads of foamed plastic may be closer or more densely
packed in the proximity of the main side surfaces compared to closer to a
plane parallel to the main side surfaces located in the centre between
the main side surfaces.

[0068] The pores present between the beads forming a network for drainage
of water may be gradually increasing in size going inwards from anyone of
the main side surfaces.

[0069] The board may be less porous in the proximity of the main side
surfaces compared to closer to a plane parallel to the main side surfaces
located in the middle between the main side surfaces.

[0070] Thus, water may be focused away from the main side surfaces towards
a centre plane parallel to and between the main side surfaces. Thus,
water in the board may be drained through the board away from the main
side surfaces. With reference to FIGS. 2a and 2b another embodiment of
the invention is hereby discussed, exemplifying use of the boards
according to the invention. It will be evident that the boards may be
used as building materials whereby damages from water on the boards
and/or other undesired effects are reduced, minimised or avoided. FIG. 2a
illustrates two boards 1 and 1', and in this example the boards are
identical to the board discussed above regarding FIG. 1. It is realised
that the discussions below also may concern other types of boards
according to the invention. In analogy with the discussions above
concerning FIG. 1, water present in the top board 1 will be drained
downwards through the top board 1, and reach the bottom side portion 4 of
the top board 1, and leave the top board 1 through the bottom side
portion 4, wherein a major part of the water will leave the board 1 at or
in the proximity of the free end 6 of board 1 extending in the
longitudinal direction of the board 1, which free end 6 only to a small
extent is visible in FIG. 2a. In FIG. 2b, wherein water is schematically
illustrated as black dots 8, a positive effect of the water leaving the
board 1 at or in the proximity of the free end 6 is illustrated.

[0071] The water 8 enters the lower board 1' just below the free end 6 of
board 1 and thus enters the board 1' in the centre of the board 1'
between the main side surfaces 3 and 3'. The water will therefore be
drained through board 1' at a distance from the main side surfaces 3 and
3'. One result of this is that wetting of the main side surfaces 3 or 3'
and/or any material in contact with the main side surfaces 3 or 3' is
reduced, minimised or avoided. It is realised that more than two boards 3
may be positioned together. For example 1, 2, 3, 4, 5, 5-10, or more
boards may be positioned stacked together. Not only is the water focused
by the tapering towards the free end 6. Focusing of the water may be
realised as a result of the groove 2 being provided in the top side
portion 7 with a shape complementary to the shape of the tapering bottom
side portion 4.

[0072] It is realised that there are several benefits with water leaving a
board at a distance from the main sides 3 and 3', as discussed above,
other than avoiding damages in the proximity of the surfaces 3 and 3'.
For example, collecting of the water leaving a lowermost board 1 in a
stack of two or more boards may be easier, as the output of water from
the board is controlled and occurs at the defined area of the free end
extending in the longitudinal direction of the board.

[0073] FIGS. 3a to 3d illustrates different embodiments of the board
according to the invention, differing in the bottom side portion 4. FIG.
3a illustrates a board 1 having a bottom side portion 4 having a V-shaped
cross-section, FIG. 3b illustrates a board 1 having a bottom side portion
4 having a W-shaped cross-section, FIG. 3c illustrates a board 1 having a
bottom side portion 4 having a U-shaped cross-section, and FIG. 3d also
illustrates a board 1 having a bottom side portion 4 having a V-shaped
cross-section. Note that the bottom side portion according to FIG. 3d
differs from the bottom side portion according to FIG. 3a, although the
two bottom side portions both have a V-shape.

[0074] FIGS. 4a to 4c illustrates different embodiments of the board
according to the invention, differing in the bottom side portion 4. Each
board has a groove 2 provided in the top side portion 7 complimentary to
the shape of the bottom side portion. FIG. 4a illustrates a board 1
having a V-shaped cross-section, FIG. 4b illustrates a board 1 having a
W-shaped cross-section, FIG. 4c illustrates a board having a U-shaped
cross-section, and FIG. 4d also illustrates a board 1 having a V-shaped
cross-section. Note that the bottom side portion according to FIG. 3d
differs from the bottom side portion according to FIG. 3a, although the
two bottom side portions both have a V-shape.

[0075] With reference to FIG. 5 a comparative example is now discussed.

EXAMPLE

[0076] From this example it will be apparent that a board according to the
invention having a bottom side portion being tapered towards a first free
end extending in the longitudinal direction of the board, the first free
end being located between planes coinciding with the main side surfaces,
has several benefits.

[0077] It has been found that a board according to the invention retains
less water compared to a board without the tapering, as is evident from
comparative experiments. Two boards were provided, boards A and B. The
only difference between boards A and B was that board A was according to
the invention with a bottom side portion having a V-shaped cross-section,
as schematically illustrated in FIG. 3a, while board B was not according
to the invention and did not have a bottom side portion being tapered but
instead had a flat horizontal bottom. Both boards were weighed dry. Water
was poured evenly across the top of the boards, which water was drained
downwards through the boards A and B. It was noted that the water poured
on board A left the board concentrated to the point of the V, thus at a
distance from the side surfaces. The water poured on board B left the
board spread out over the flat horizontal bottom.

[0078] The boards A and B was left for several hours in upright position,
after which the boards where weighed a second time. It was determined
that board A had gained considerably less in weight, compared to board B.
The gain is weight was concluded to be water remaining in the boards.
Thus it is concluded that board A retains considerably less water
compared to board B.

[0079] It was further noted that a major part, or all, of the water
remaining in the boards A and B was confined to the bottom side portion,
that the water was present in the network of pores between the beads of
foamed plastic, and that the water was present from the lowermost point
of the board and extending 15 mm upwards, possibly at least partly as a
result of capillary forces of the board, as illustrated in FIG. 5.
Thereby, the bottom side portion being tapered of board A, results in
less water being retained compared to the other board B.

[0080] According to an alternative embodiment the beads of foamed plastic
used in the boards disclosed in the embodiments discussed above may be
replaced by beads of any other suitable foamed material for the
insulating and draining board. For example, such foamed material may be
selected from glass, glass mineral, such as perlite, ceramic material,
and graphite, or any combination thereof.

[0081] Further aspects of the present invention will now be discussed with
references to the following items: [0082] Item 1: An insulating and
draining board (1) with two opposing main side surfaces (3) and a top
side portion (7) and a bottom side portion (4),

[0083] said board being formed by bonded foamed beads, wherein pores are
present between the beads forming a network for drainage of water,

[0084] wherein the pores exhibit a pore size varying in a thickness
direction of the board.

[0085] As the pore size have an effect on the draining of water, thus, the
draining of water may vary in a thickness direction of the board. For
example, water may be more efficiently drained in the center of the
board. Further, water may be more efficiently drained away from one or
both of the main side surfaces. A larger pore size may more efficiently
drain water.

[0086] According to one embodiment of item 1, the pores may exhibit a
smallest pore size in at least a plane associated with one of the main
side surfaces of the board. Thus, water may be drained away from one of
the main side surfaces.

[0087] According to another embodiment of item 1, the pores may exhibit a
smallest pore size in planes associated with both main side surfaces of
the board. Thus, water may be drained away from both of the main side
surfaces.

[0088] According to another embodiment of item 1, said beads may be
exhibiting a uniform bead size, wherein beads present in said at least a
plane associated with at least one of the main side surfaces of the board
may be more densely packed in order to achieve said smallest pore size.
Thus, water may be drained away from one of the main side surfaces.

[0089] According to another embodiment of item 1, said beads may be
exhibiting a non-uniform bead size, wherein beads present in planes
associated with one or both main side surface(s) of the board may have a
smaller average diameter in order to achieve said smallest pore size.
Such a smaller average diameter may be an efficient way of obtaining
smaller pores between the beads, as compared to beads with larger average
diameters. Thus, draining of water may be focused away from the proximity
of one or both main side surfaces, as the water may be drained with less
resistance through larger pores.

[0090] According to another embodiment of item 1, the pores present
between the beads forming a network for drainage of water may be
gradually increasing in size going inwards from anyone of the main side
surfaces. For example as the result of the average diameter of the beads
increasing or the beads being less densely packed going inwards from
anyone of the main side surfaces.

[0091] Thus, as the result of item 1 and the embodiments of item 1 the
pores present between the beads may be small in the proximity of one or
both main side surfaces. Thus, draining of water may be focused away from
the proximity of one or both main side surfaces, as the water may be
drained with less resistance through larger pores.

[0092] For example, the beads may have an average diameter below 7 mm, for
example, the beads of foamed plastic may have an average diameter between
7 and 4 mm, or below 4 mm such as an average diameter below 1 mm. All
beads may be below 7 mm. Beads with such sizes may provide efficient
insulation properties. Further, beads with such average diameters may
provide efficient draining of water. Yet further, beads with such average
diameters may provide boards with high strength.

[0093] According to another embodiment of item 1, the beads may be made of
a material selected from the group consisting of glass, glass mineral,
such as perlite, ceramic material, graphite and plastic material, or
combinations thereof. Thus, the material may be selected to provide high
resistance against pressure loads by choosing for example a ceramic
material. Further a material may be selected such that the board has
particularly low weight, for example by choosing plastic material. Yet
further the material may be chosen to efficiently provide resistance
against fire or heat.

[0094] The board according to item 1 may have an essentially rectangular
cross-section in a vertical plane perpendicular to the main side
surfaces. The board may be provided with means for facilitating
arrangement with another board, such as tongue and/or groove. For example
the board may have a form of a right parallelepiped. [0095] Item 2: An
insulating and draining board (1) with two opposing main side surfaces
(3) and a top side portion (7) and a bottom side portion (4),

[0096] said board being formed by bonded beads arranged in at least two
layers being parallel to said main surfaces, wherein pores are present
between the beads forming a network for drainage of water,

[0097] wherein a property of one of said at least two layers is different
from the corresponding property of another of said at least two layers,
the property being selected from the group consisting of bead material,
binding agent, average diameter of beads, pore size, and degree of close
packing of the beads, or combinations thereof.

[0098] Thus, the board may have different desired properties in different
layers. For example the board may have outer layers protecting from heat
and/or water, and an inner layer providing efficient draining of water.

[0099] According to one embodiment of item 2, the bead material may be
selected from the group consisting of glass, glass mineral, such as
perlite, ceramic material, graphite and plastic material, or combinations
thereof. Thus, the material may be selected to provide high resistance
against pressure loads by choosing for example a ceramic material.
Further a material may be selected such that the board has particularly
low weight, for example by choosing plastic material. Yet further the
material may be chosen to efficiently provide resistance against fire or
heat.

[0100] According to another embodiment of item 2, the beads of at least
one layer may comprise foamed beads. Thus, the beads in one, several or
all layer(s) may be foamed.

[0101] According to another embodiment of item 2, the board may comprise
several layers, such as 2; 3 or less; 4 or less; 5 or less; or 5 or more
layers. Thus, for example, the board may comprise three layers with a
layer of beads with smaller average diameter, such as beads with an
average diameter of less than 4 mm at one of the main side surfaces, a
layer of beads with larger average diameter, such as beads with an
average diameter of between 7 and 4 mm, closer to the center of the
board, and a layer of beads with smaller average diameter, such as beads
with an average diameter of less than 4 mm, at main side surface 3,
further the beads in the different layers may be made of different
materials.

[0102] According to another embodiment of item 2, each layer may
individually have a thickness of 90% or less of the thickness of the
board, such as 75% or less, 50% or less, 25% or less or 10% or less.
Thus, for example, the board may comprise three layers of which one layer
may have a thickness of 50% of the thickness of the board, another layer
may have a thickness of 25% of the thickness of the board and yet another
layer may have a thickness of 25% of the thickness of the board. It may
be preferred the multilayered board may have a uniform layer thickness.
According to another embodiment of item 2, the board may have an
essentially rectangular cross-section in a vertical plane perpendicular
to the main side surfaces. The board may be provided with means for
facilitating arrangement with another board, such as tongue and/or
groove. For example the board may have a form of a right parallelepiped.

[0103] It is realised that the discussions concerning the board having a
bottom side portion of the board being tapered towards a first free end
(6) extending in the longitudinal direction of the board, the first free
end (6) being located between planes coinciding with the main side
surfaces (3) may be relevant for other aspects of the invention,
including items 1 and 2 and their embodiments, and references to these
discussions are hereby made. It is further realised that the discussions
and embodiments concerning item 1 may be relevant with regards to item 2
and vice versa, and references to these discussions are hereby made.
Different embodiments of item 1 may be combined. Different embodiments of
item 2 may be combined.